See that “FAN/DATA” port? A common micro USB cord is all that's required to hook up the Tekin HotWire!

Tekin is a prime example of an RC manufacturer that uses its experiences on the track to develop improvements to its entire product line. The biggest benefactor of that process is their new flagship RSX speed control. Everything from the material used to make the case, to the way that the optional fan can be mounted, to the technology inside and how Tekin's HotWire system interfaces with it has been optimized for better performance, and the overall package demonstrates Tekin's attention to detail. Packed with refined technology to better handle the rigors of racing and anything that a backyard hero can throw at it, Tekin's new RSX runs cooler and looks better than anything else they make — and that's why it's at the top of their range.

Tekin was so committed to the red/black motif that the circuit board is also red! Note the sensor port, which is hidden underneath the solder posts.

The included fan is protected by a shiny red “X.” Cool!

Even with its beefed up tolerance for hot modified power (that exceeds what the RS Pro could handle), Tekin intends the RSX as a racing unit for 1/10-scale vehicles — as clearly evidenced by the “4 lb. chassis” limit listed next to the RSX's motor and battery limits on the spec charts. Two-wheel drive short course trucks, when fully outfitted, are right around the four-pound mark — and those are the heaviest vehicles that Tekin intends to be used with the RSX, effectively ruling out 4WD short course trucks, which are better outfitted with 1/8-scale speed control units and 4-pole motors.

The striking aluminum case and diagonally finned heatsink of the RSX is only slightly larger than Tekin's RS line, at 1.2 × 1.5 inches. The RSX uses the same additional capacitor as well, so it's really no different to install than the RS or RS Pro — except for the sensor port, which is now underneath the solder posts, so you'll need to consider that when determining where to tape it to the chassis and most likely plug the cable into the RSX before you fasten it into place. The optional fan shroud is included and bolts to the unit's heat sink for further cooling, adding about a half an inch to its height, but may not be necessary in many applications. Among the reasons the sensor plug was moved is the new micro USB data/fan port, which is easily accessible and allows the RSX to be plugged directly into the HotWire unit without using the speed control's receiver plug — a welcome change! The tall solder posts are back, and make it easy to install the battery and motor wires with a bit of handy solder work.

SETTING UP THE RSX

The RSX comes with the required power capacitor, optional fan, and everything you'll need for the install. Take your time when deciding where to tape it in place, and be aware of the sensor port!

TUNE WITH YOUR ANDROID DEVICE

If you've got an Android smartphone or tablet, you can leave your laptop at home. In order to use the new HotWire Lite app (available on Google Play), you'll need the HotWire device (TT1450, $32), the proper USB OTG cable for your phone or tablet, and a Gen2 speed control (RX8 Gen2, RS Gen2, RS Spec, or RSX). The app works just like the full version of HotWire, allowing you to adjust throttle and timing parameters, voltage cutoff, BEC voltage, and more — and it's free!

TESTING

Joel Navarro and I tested the RSX in a few different capacities to see how well it worked, and it passed our heavy scrutiny with flying colors. First taped into a 2WD buggy with a 17.5 system, no amount of timing advance triggered excessive heat or fade throughout a run, with smooth acceleration and precise braking feel throughout each test run. It was more of the same with an 8.5 motor and more than enough power to overwhelm our test track, again not generating any noticeable heat despite not having the fan installed! It wasn't until running the RSX in a 4WD buggy with a 5.5-turn motor on the receiving end of its motor leads that we installed the fan, and even that amount of overkill didn't upset the RSX after several packs of abuse. Without worrying about hiccups or rising temperatures, I was able to focus on improving my laptimes — which is what investing in competition-caliber gear such as the Tekin RSX is all about.

Programming the RSX to work with your transmitter is as easy as ever, requiring one button push and a cycle through the trigger's travel range to set neutral, full throttle, and full brake. However, counting LEDs to adjust the speed control's seven QuickTune modes is a bit tedious. Tekin's new Hot-Wire Android app makes it a snap! The app will work with all of Tekin's speed controls and is one of this unit's best selling points, along with the new high-voltage BEC that finally takes advantage of today's 7.4V-ready servos. If you've got an HV servo installed, it will probably take you several runs to get used to the extra performance of those added 1.4 volts.— Aaron Waldron

About the author

Associate Editor
Since receiving my first hobby-grade RC car as a holiday present from my father nearly 20 years ago, I've been fortunate enough to meet more people and experience more opportunities through the adventures I've had in the RC industry than I would've ever imagined. I've done it all - from working at a hobby shop, to being a factory sponsored racer, to working for some of the biggest brands in the industry. I've enjoyed each and every one of the dozens of kits I've built, hundreds of events I've attended, and thousands of laps that I've logged at race tracks around the world, and my passion is to share those experiences with other hobbyists so that they may find fulfillment in their own RC careers.